Can anyone work out number 2 and 4 thanks :)

Ineed if you could explain and give me the answer you! this needs done

Terri makes a quilt using three sizes of fabric squares the side lenght of each fabric square is the square root of the area

Factor the polynomial 4x4 – 20x2 – 3x2 + 15 by grouping. what is the resulting expression? (4x2 + 3)(x2 – 5) (4x2 – 3)(x2 – 5) (4x2 – 5)(x2 + 3) (4x2 + 5)(x2 – 3)